RailFast Antenna Mounts Quick, easy installation of antenna on 1" or 7/8" railing. Ideal for G.P.S., VHF radio, and whip antennas, has direct feed-thru hole for coax cable. Ratchet surface permits 360° rotation for adjustment/lay-down. Holds antennas up to 8' (2.4 meters) in length. No drilling required; all necessary hardware provided.